Paper clamping device



May 2, 1939- w. H. slNcLAlR 2,156,404

' PAPER CLAMPING DEVICE Filed Deo. 16, 1936 l /LZ f1 la www@ www n EPatented May 2, 1939 UNiTED STATES PATENT OFFICE PAPER CLAMPING DEVICEWilliam Horace Sinclair, Los Angeles, Calif.

Application December 16, 1936, Serial No. 116,166

10 Claims. (Cl. 45-131) My invention relates to drawing boards pro- 9,so as to providea rounded edge. To strengthen vided with means whereby asheet of paper on the guide rail i and to add resiliency thereto I thedrawing board may be clamped in position prefer to press into the sheetmetal a longituby means or" clamping members which slide on dina1- ribI6 located intermediate the vertical 5 a pair of guide rails attached tothe sides of portion 5 and the bottom of the trough 8. It .5` thedrawing board. should be noted that the vertical portions 5 and It is anobject of this invention to provide the free end extending outwardlytherefrom and simple and efcient means whereby an ordinary forming thetrough 8 lie between two horizontal drafting board may be provided withmeans complanes, which confine a space between the bot- 10 prising apair of clamping bars extending transtom of the drawing board I andabout one- 1'0 versely across the board and which may be inthird of theheight of the SdeS Oi the drawing stantly adjusted by sliding themacross the face beard. of the board, the clamping bars having pivoted Aclamping bar II preferably made of Sheet arms in slidable engagementwith resilient guide metal eXterldS traIlSVerSeiY and at right anglesrails, the arms and resilient guide rails being so to the sides 2 and 3of the drawing board. L 15: constructed that a tension is exerted uponthe termedate itSendS, disposed irl the middle, is a clamping bartending to press downwardly upon longitudinal rib I2 which serves to addstrength the paper, thus holding it securely in place, to the barA IIand also tends to force the clamp- With the above and other objects inView,Y ing bar dOWnWardiy UDCH the draWmg board which will appear as thedescription proceeds, When any 'tension iS eXerted irl Opposite direczomy invention consists in the construction, artions at the ends of the`clamping bar ii. rangement and combination of parts hereinafter TheClamping bar ii iS preferably faed with described. Y felt i3. It shouldbe observed here that as In the accompanying drawing, which forms ashown in Fig. 6 the felt does not extend clear part ofthe specication,1have illustrated a preaClOSS the Clamping bar ii immediately below 25ferred embodiment of my invention, and in the rib i2 but only along theat DDriiOrlS latwhich. erally extending from the rib I2. This construc-Fig. l is a top plan View of a portion of a drafttion permits the rib ilt0 eXparld Slightly latering board equipped with my invention. ally,thus hugging the drawing board. If the l 2 is@J vertical Section on theline 2..-2 0f felt I3v extended clear across underneath rib I2 30 Fig 1such spreading action would be prevented.

Fig, 3 is a perspective view of a section of the The ends of theclamping bar il are reducedv guide rail. to form tongues at I-Iii turnedinwardly on Fig. 4 is a fragmentary View in perspective of top of theclamping bar Il and serve as hooks the clamping bar. for the receptionof clamping armsI-I which VV-35 Fig. 5 is a perspective View of one ofthe clampare provided at their inner ends with apertures ing arms. IBthrough which the tongues Ill hold arms I5 Fig. 6 is a detailed sectionon an enlarged scale in pivotal relation to the bar II and permit thetaken on the line 6 6 of Fig. 2. v arms to swing in a vertical plane.The outer end 40 Referring to the drawing, I indicates a drawof arms I5is curved as at ll and of a shape to 4,0 ing board of conventionalconstruction, preferengage the lower face of the trough S of the ablymade of wood and provided with parallel, guide rails 4. vertical sides 2and 3. A guide rail 4 fastened A longitudinal rib I8 on arm i5corresponds in to the sides 2 and 3 extends the total length of size andposition to rib lo in the guide rail and such sides. The guide rail 4 ispreferably made is in engagement therewith. To facilitate the ofresilient sheet metal and comprises a Vertical Sliding movement betweenarms I5 along the portion e which lies flat against the lower perguideradis 4, lugs I9 are provided which extend tion of s1des E and 3 and 1ssecured thereto by vertically upward from arms I5 to form manual meansof fastening member, such as wood screws grips for the thumb and fingerin moving the 6 passing through perforations I of the vertical Clampalong the guide mils 4l 5o portion 5.

From the upper end of vertical portion 5 the Operation sheet metalextends downwardly-and outwardly The operation of the paper clamp isobvious to form a trough or channel 8, the free end of from theforegoing description. Apaper is placed the sheet metal being turnedupon itself as at I on the drawing-board-I and by sliding the arms l5and clamping bar l I pivoted thereto the paper clamp is moved to thedesired position. It will be understood that it may be desirable rto usea pair of clamps on the same drawing board at opposite ends of the paperto be held in place. For smaller sheets, one clamp will ordinarily besufficient. It should be noted that due to the resiliency of the guiderails 4 clamping bar Il is yieldingly= forced down upon the paper. Theguide rails it, due to the trough shaped conguration may serve also forthe reception of pencils, drawing instruments, and the like, and inorder to prevent such articles from sliding off the trough 8 if theboard is in an inclined position, spaced portions 29 forming slightprotuberances on the upper surface of the trough 8 may be provided toafford frictional resistance.

By providing the clamping member with a central clamping bar l l and apair of arms pivoted to the ends thereof, the cost of manufacture isreduced. It will be only necessary in order to accommodate drawingboards of different widths to provide clamping bars Il of variouslengths to accommodate the standard sizes of drawing boards, the guiderails and arms l5 being of the same size for all drawing boards.

It should also be noted that a T-square may be used on the drawing boardin the usual manner since the guide rail is considerably below the planeof the head of the T-square. While the invention is primarily intendedfor use with drawing boards and tables, it is of general application andcould be used for instance on tables used for cuttingout of dresspatterns in holding both the pattern and the dress goods clamped to thetable. Therefore the term drawing board in the claims is intended tocover any plane surface having two parallel sides to which the guiderails may be attached.

Various changes in the construction and arrangement of parts of myimproved paper clamping device may be made by those skilled in the artwithout departing from the spirit of my invention as claimed.

E claim: Y

l. The combination of a drawing board having parallel sides providedwith guide rails, each guide rail being made of resilient sheet metalhaving a vertical, longitudinal portion fastened tothe lower portion ofthe side, the sheet metal extending from the upper end of the verticallportion outwardly and downwardly to form a trough open at the top, asheet metal bar extending transversely of the board, sheet metal armspivoted to the ends of the clamp bar, said sheet metal arms being curvedto correspond to the curvature of the guide rails and engaging thelatter in slidable contact on the outer face of the trough.

2. The combination of a drawing board having parallel sides providedwith guide rails, each guide rail being made of sheet metal having alongitudinal portion fastened to the lower portion of the side andextending downwardly and outwardly therefrom to form a trough, a sheetmetal clamp bar extending transversely of the board and provided with alongitudinal, central rib extending upwardly therefrom, and arms made ofresilient sheet metal pivoted to the ends of the clamp bar and beingcurved to correspond to the curva-Y ture of the trough and engaging theexterior face thereof in sliding relation, said arms being provided withupstanding lugs to form manual grips for moving the clamp bar and itsarms longitudinally in relation to the drawing board.

3. A drawing board having a flat top working surface and parallel sideedges at right angles to the top, a resilient guide rail fasteneddirectly to each side edge and each extending longitudinally of suchedge, each complete guide rail being located below the top of the boardto permit use of a T-square, a clamp extending transversely over the topof the board from side to side and detachable connecting means securingeach end of the clamp to the adjacent guide rail, said attaching meansand the clamp being slidable longitudinally of the board.

4. A drawing board as claimed in claim 3, each guide rail forming atrough open at the top adapted to receive drawing instruments, the clamphaving a hook at each end, the attaching means of the clamp to the guiderails including resilient arms each attached to a hook and engaging eachunderneath a guide rail.

5. In a drawing board having a at top working surface and parallel sideedges at right angles thereto, a sheet metal guide rail secured to eachside and having an outwardly extending portion, the outer portion beingslightly bendable upwardly and the whole of each guide rail being belowthe top of the board whereby a T- square may be Iutilised on the boardand have a head engaging an edge of the board, a clamping bar extendingacross the top of the board from edge to edge and having a hook on eachend, a resilient clamping arm pivoted to each hook and having means toengage the outer portion of the adjacent sheet metal guide rail, eachclamping arm being slidable longitudinally of the guide rail forshifting the clamping bar. V

6. In a Vdrawing board as claimed in claim 5, the outer portion of eachsheet metal guide rail having an upwardly facing trough and alongitudinal ribA extending upwardly between the trough portion and theedge of the drawing board, each clamping arm having a downwardly curvedend to t underneath the trough and having an upwardly extending rib toengage under the rib of the guide rail.

7. In a drawing board as claimed in claim 5, the clamping bar having anupwardly pressed, longitudinal rib, a felt between the under surface ofthe clamping bar and the drafting board, such felt having an openingunderneath the rib whereby on a downward pull on the ends of theclamping bar due to the action of the clamping arms and the hooks thesection of the clamping bar having the longitudinal rib may expandslightly laterally.

8. In a drawing board clamp, a clamping bar formed of sheet material ofsubstantially constant thickness, the bar being comparatively narrowconsidered laterally compared with its length across the board, themajor portion of the clamp being in aplane surface except the centerportion of the clamping bar having an upwardly extending rib, such ribextending longitudinally of the clamping bar and positioned centrally asto its lateral edges, a felt engaging the under surface of the clampingbar and having an opening underneath the rib, and resilient meansengaging the ends of the clamping bar to pull the bar towards thesurface of the drafting board, the portion of the bar at the rib beingadapted to expand slightly laterally.

9. In a drawing board having parallel sides, the combination of twoguide rails each formed of a trough shaped resilientl sheet of metal andeach having attachments to the board extending longitudinally of thechannels, the said channels forming a trough open at the top, a clampbar extending transversely of the board and having means for engagingthe undersides of the channel shaped guide rails and slidable thereonfor sliding the clamp longitudinally of the drawing board.

10. In a drawing board having a Ailat top and parallel sides, combinedwith a pair of guide rails on each side or" the board and havingattaching means to the board, said guide rails being resili- 0 ent as toup and down movement from the attaching means, a clamp bar extendingtransversely of the board, resilient arms pivoted to the ends of theclamp bars by a horizontal pivot whereby the resilient arms swing on thepivots in vertical planes, each resilient arm having means to engage andattach to one of the resilient guide rails and thereby exert a downwardpull on the clamping bar.

WILLIAM HORACE SINCLAIR.

